CFD simulation of electrostatic effect on gas interchange, vortex and heat transfer in the gas-solid fluidized bed

摘要

Vortex and electrostatic charges in the gas-solid fluidized bed have a significant influence on its transport abilities and hydrodynamics. In this work, the electrostatic model coupled with energy model has been applied to reveal the electrostatic effect on hydrodynamics, vorticity and local heat transfer coefficients based on the kinetic theory of granular flow. The results indicate that particle vortices change the gas and solid phase interaction around the bubble and enhance the local heat transfer coefficients. Gas interchange decreases by 6.5% compared to Davidson model at the jet velocity of 10 m center dot s (1) and 13% of 5 m center dot s (1). After adding electrostatic charges, bubble diameter decreases with the increasing specific charges. Furthermore, vorticity at the initial stage of bubble formation is larger and the particle vortex diffuses to a large extent. The simulation results can be applied to modify and estimate the overall heat transfer coefficient of the fluidized bed reactor and provide the basis for studying the effect of electrostatic effect on heat transfer. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.